Lumber cutter for removing end defects and sawing to desired lengths

Abstract

There is disclosed saw mill apparatus for cutting root end defects from lumber pieces and cutting such pieces to desired sizes including a generally conventional scanner for recording detailed contour data for each piece as it is moved by a plurality of chain belt conveyors transverse to its longitudinal dimension; the scanner is followed by a root end trim saw unit extending over the root end edge of such conveyors including a motor driven rotating circular saw blade articulated to move down into or up out of the path of lumber pieces and also slidably mounted to be moved over a range of about 24 inches in one half inch increments thereby to cut away a defective portion of a lumber piece identified by the scanner and a conventional mill computer; following the end trimming saw unit is an even ending apparatus with generally conventional ending rolls to transport lumber pieces lengthwise as necessary to butt the root end against a guide fence. The guide fence positions the lumber pieces' root ends at the same, or nearly the same, position for entering a generally conventional sizing saw array unit where a wafer cut is made by a zero-line saw on the root end of the lumber piece as necessary, and selected ones of the sizing saws are lowered into operative position to cut the lumber pieces to the desired sizes for optimum value.

What is claimed is: 
     
       1. Apparatus for accepting lumber pieces from a scanner and for cutting away end defects thereof, each of said lumber pieces having a longitudinal dimension and a root end, comprising: a conveyor including a plurality of endless belts for conveying lumber pieces transverse to their longitudinal dimension along a path from said scanner to an output end, said belts being generally horizontal, parallel, having a length extending along the direction of conveyance, and spaced apart by no more than eight feet,   a butt trimmer saw assembly juxtaposed with said conveyor, said assembly including a saw movably mounted for axial motion transverse to the length of said belts, with a blade of said saw positionable to intercept and cut said lumber pieces at or near their ends, the controllable axial motion of said saw being at least six inches,   said saw having a blade movably mounted to move vertically into and out of the path of said lumber pieces,   an actuator for moving said saw blade vertically between operative and inoperative positions,   means for producing axial motion of said saw to a desired position,   means for frictionally contacting said lumber pieces and moving them lengthwise transversely to the length of said belts in the direction of their root ends,   a fence positioned to serve as a stop for said lumber pieces, said fence including a vertical barrier extending parallel to the length of said belts for at least two feet, and   electronic control apparatus connected to receive signals from said scanner and generate signals responsive to the received signals for controlling said actuator for moving said saw blade vertically and said means for producing axial motion of said saw.   
     
     
       2. Apparatus as recited in claim 1 wherein said saw blade is rotatably secured on an arm which is pivotally mounted on said assembly to move vertically between operative and inoperative positions for said saw blade. 
     
     
       3. Apparatus as recited in claim 1 wherein said means for producing axial motion of said circular saw to a desired position includes a servo-mechanism under electronic control coupled to drive means for causing linear motion of said saw parallel to its axis. 
     
     
       4. Apparatus as recited in claim 1 wherein said means for frictionally contacting said lumber pieces includes a set of crossdrive elongated rollers positioned downstream of said saw assembly and having longitudinal axes substantially parallel to the length of said belts positioned for frictional contact with said lumber pieces. 
     
     
       5. Apparatus as recited in claim 1 wherein said fence includes a vertical barrier extending parallel to the length of said belts and means for causing said barrier to move with a velocity and direction approximately the same as that of said belts. 
     
     
       6. Apparatus for accepting lumber pieces from a scanner and for cutting away end defects thereof, each of said lumber pieces having a longitudinal dimension and a root end, comprising: a conveyor including a plurality of endless belts for conveying lumber pieces transverse to their longitudinal dimension along a path from said scanner to an output end, said belts being generally horizontal, parallel, having a length extending along the direction of conveyance, and spaced apart by no more than eight feet,   a butt trimmer saw assembly juxtaposed with said conveyor, said assembly including a saw movably mounted for axial motion transverse to the length of said belts, with a blade of said saw positionable to intercept and cut said lumber pieces at or near their ends, the controllable axial motion of said saw being at least six inches,   said saw having a blade movably mounted to move vertically into and out of the path of said lumber pieces,   an actuator for moving said saw blade vertically between operative and inoperative positions,   means for producing axial motion of said saw to a desired position,   means for frictionally contacting said lumber pieces and moving them lengthwise transversely to the length of said belts in the direction of their root ends,   a fence positioned to serve as a stop for said lumber pieces, said fence including a vertical barrier extending parallel to the length of said belts for at least two feet,   electronic control apparatus connected to receive signals from said scanner and generate signals responsive to the received signals for controlling said actuator for moving said saw blade vertically and said means for producing axial motion of said saw, and   a second fence positioned downstream of said first fence, said second fence having upstream and downstream ends, the downstream end of said second fence being movable in response to electronic control to adjust the position of said root ends of said lumber pieces selectively by an amount of at least about one-quarter inch.   
     
     
       7. Apparatus as recited in claim 6 further including an array of selectively operable cut-off saws positioned near the output end of said conveyor, and means for operatively positioning certain ones of said saws while positioning others of said saws in inoperable position. 
     
     
       8. Apparatus as recited in claim 7 further including a fixed end trimmer saw positioned substantially in alignment with said second fence, such that the position of said second fence determines whether the end of a given lumber piece is intercepted by and cut by said fixed end trimmer saw, and electronic control apparatus connected to receive signals from said scanner and generate signals responsive to the received signals for controlling said butt trimmer saw assembly, said second fence, and said cut-off saws. 
     
     
       9. Apparatus for accepting lumber pieces from a scanner and for cutting away end defects thereof, each of said lumber pieces having a longitudinal dimension and a root end, comprising: a conveyor for conveying lumber pieces from the scanner to an output end and including a plurality of endless belts having lugs for engaging lumber pieces, said belts being generally horizontal, parallel, having a length extending along the direction of conveyance, and spaced apart by no more than four feet,   a butt trimmer assembly juxtaposed with said conveyor remote from the output end thereof, said assembly including crosscutting means movably mounted for motion transverse to the length of said belts, the controllable transverse motion of said crosscutting means being at least one foot,   means for controlling said crosscutting means to render it operative to cut one of said lumber pieces,   means for producing transverse motion of said crosscutting means to a desired position under electronic control,   means positioned downstream of said trimmer assembly for frictionally contacting said lumber pieces and moving them lengthwise transversely to the length of said belts,   a fence positioned to serve as a stop for said lumber pieces, said fence including a vertical shock absorbing barrier extending parallel to the length of said belts for at least two feet, and   electronic control apparatus connected to receive signals from said scanner and generate signals responsive to the received signals for controlling said crosscutting means operative condition and for controlling said means for producing transverse motion of said crosscutting means.   
     
     
       10. Apparatus as recited in claim 9 wherein said crosscutting means is a saw and further including an actuator for moving said saw blade vertically between operative and inoperative positions. 
     
     
       11. Apparatus as recited in claim 9 wherein said means positioned downstream of said trimmer assembly for frictionally contacting said lumber pieces includes a set of cross-drive elongated rollers having longitudinal axes substantially parallel to the length of said belts. 
     
     
       12. Apparatus as recited in claim 9 wherein said fence further includes means for causing said barrier to move with a velocity and direction approximately the same as that of said belts. 
     
     
       13. Apparatus for accepting lumber pieces from a scanner and for cutting away end defects thereof, each of said lumber pieces having a longitudinal dimension and a root end, comprising: a conveyor for conveying lumber pieces from the scanner to an output end and including a plurality of endless belts having lugs for engaging lumber pieces, said belts being generally horizontal, parallel, having a length extending along the direction of conveyance, and spaced apart by no more than four feet,   a butt trimmer assembly juxtaposed with said conveyor remote from the output end thereof, said assembly including crosscutting means movably mounted for motion transverse to the length of said belts, the controllable transverse motion of said crosscutting means being at least one foot,   means for controlling said crosscutting means to render it operative to cut one of said lumber pieces,   means for producing transverse motion of said crosscutting means to a desired position under electronic control,   means positioned downstream of said trimmer assembly for frictionally contacting said lumber pieces and moving them lengthwise transversely to the length of said belts,   a fence positioned to serve as a stop for said lumber pieces, said fence including a vertical shock absorbing barrier extending parallel to the length of said belts for at least two feet,   electronic control apparatus connected to receive signals from said scanner and generate signals responsive to the received signals for controlling said crosscutting means operative condition and for controlling said means for producing transverse motion of said crosscutting means, and   a second fence positioned downstream of the said first fence, said second fence having upstream and downstream ends, the downstream end of said second fence being movable in response to electronic control to adjust the position of said root ends of said lumber pieces selectively by an amount of at least about one-quarter inch.   
     
     
       14. Apparatus as recited in claim 13 further including an array of selectively operable cut-off saws positioned near the output end of said conveyor, and means for operatively positioning certain ones of said saws while positioning others of said saws in inoperable position. 
     
     
       15. Apparatus as recited in claim 14 further including a fixed root-end trimmer saw positioned substantially in alignment with said second fence, such that the position of said second fence determines whether the root end of a given lumber piece is intercepted by and cut by said fixed root-end trimmer saw, and electronic control apparatus connected to receive signals from said scanner and generate signals responsive to the received signals for controlling said second fence and said cut-off saws. 
     
     
       16. Apparatus for accepting lumber pieces from a scanner and for cutting said pieces to length, each of said pieces having a longitudinal dimension and a root end, comprising: a conveyor for conveying lumber pieces along a path from the scanner to an output end and including a plurality of endless chain belts having lugs for engaging lumber pieces, said belts being generally horizontal, parallel, having a length extending along the direction of the conveyance, and spaced apart by no more than four feet,   a butt trimmer saw assembly juxtaposed with said conveyor remote from the output end thereof, said assembly including a circular saw slidably mounted for movement along a path of axial motion transverse to the length of said chain belts, with a blade of said saw positionable to intercept and cut said lumber pieces at or near their root ends, the controllable axial motion of said circular saw being at least one foot,   said circular saw having a rotatable saw blade mounted on a pivot arm for permitting said blade to move into and out of the path of said lumber pieces,   an actuator for moving said saw blade vertically between operative and inoperative positions,   a servo-mechanism for producing axial motion of said circular saw to a desired position under electronic control,   a set of cross-drive elongated rollers positioned downstream of said saw assembly with their longitudinal axes substantially parallel to the length of said chain belts for frictionally contacting said lumber pieces and moving them lengthwise transversely to the length of said chain belts in the direction of their root ends,   a first fence positioned to serve as a stop for said lumber pieces,   a second fence positioned downstream of said first fence, the downstream end of said second fence being movable in response to electronic control to adjust the lateral position of said lumber pieces selectively by an amount of at least about one-quarter inch,   an array of selectively operable cut-off saws positioned near the output end of said conveyor,   means for operatively positioning certain ones of said saws while positioning others of said saws in inoperable position,   a fixed root-end trimmer saw positioned substantially in alignment with said second fence, such that the position of said second fence determines whether the root end of a given lumber piece is intercepted by and cut by said fixed root-end trimmer saw, and   electronic control apparatus connected to receive signals from said scanner and generate signals responsive to the received signals for controlling said butt trimmer saw assembly, said second fence, and said cut-off saws.   
     
     
       17. Apparatus as recited in claim 16 wherein said first fence includes a vertical barrier extending parallel to the length of said chain belts and means for causing said barrier to move with a velocity and direction approximately the same as that of said chain belts. 
     
     
       18. Apparatus as recited in claim 16 wherein said actuator for moving said saw blade includes an elongated rail structure extending parallel to the path of axial motion of said circular saw, means for mounting said rail structure to pivot through at least 30° about an axis parallel to the longitudinal dimension of said rail structure, a lever fixedly connected to said pivot arm having a rail engaging element at an end thereof engaging said rail structure in a longitudinally slidable manner, and means for moving said rail structure about its pivotal axis.